local person = { id = 0, name = "", sex = "男" }
function person:new(obj, id, name, sex)
    obj = obj or {} -- 左值为false 就返回右侧数值
    setmetatable(obj, self)
    self.__index = self
    self.id = id;
    self.name = name;
    self.sex = sex;
    return obj
end

function person:show()
    print(string.format("%d => %s : %s", self.id, self.name, self.sex))
end

return person;


